Anjuu Sendou is a nice girl who just started her first year in the Seiryuu Academy Middle School. She is currently living away from home as a boarding student with her pet named Lime. Her father is a sorcerer and her mother is an expert in Chinese kenpo. They are both famous, especially her mother who is called Dragon Momoka.

Because of her mother’s fame, the executive committee wants Anjuu to join the student council. But the council’s president thinks that she is a weak girl, so to prove him wrong she decides to catch the school thief. When things get difficult and she wishes to become stronger, her pet suddenly transforms into a small child with wings (a pre-dragon form, because Lime isn't fully grown) and tells her about her power.

The next time the school thief appears, Anjuu, with the help of Lime, transforms into a new Saint Dragon Girl, defeating the enemies and becoming the school’s protector. Will the student council’s members find out the true identity of the warrior girl? Will Anjuu be able to keep her secret?